Escalators and moving walks are equipped with starting keyswitches located at both ends. The keyswitches have two starting positions, typically lateral, for the up and down directions (in the case of escalators) and for forward and reverse (in the case of moving walks), and a spring return to a normal (center) position.
To start the escalator or moving walk, one of the keyswitches is turned to one of the starting positions, e.g., up or down, forward or reverse. After the direction circuit is latched or "sealed-in", the keyswitch is released to the normal position and the key may be removed.